CSHARP-4069: Fix flaky Misbehaved_async_method_should_not_deadlock_server_selection test. (#742)

Author: DmitryLukyanov

tests/MongoDB.Driver.Core.TestHelpers/CoreTestConfiguration.cs

@@ -43,6 +43,7 @@ public static class CoreTestConfiguration
         private static Lazy<ConnectionString> __connectionStringWithMultipleShardRouters = new Lazy<ConnectionString>(
             GetConnectionStringWithMultipleShardRouters, isThreadSafe: true);
         private static Lazy<DatabaseNamespace> __databaseNamespace = new Lazy<DatabaseNamespace>(GetDatabaseNamespace, isThreadSafe: true);
+        private static Lazy<TimeSpan> __defaultServerSelectionTimeout = new Lazy<TimeSpan>(GetDefaultServerSelectionTimeout, isThreadSafe: true);
         private static Lazy<int> __maxWireVersion = new Lazy<int>(GetMaxWireVersion, isThreadSafe: true);
         private static MessageEncoderSettings __messageEncoderSettings = new MessageEncoderSettings();
         private static Lazy<int> __numberOfMongoses = new Lazy<int>(GetNumberOfMongoses, isThreadSafe: true);
@@ -75,6 +76,21 @@ public static DatabaseNamespace DatabaseNamespace
             get { return __databaseNamespace.Value; }
         }
 
+        public static ICluster ClusterWithConnectedPrimary
+        {
+            get
+            {
+                var timeout = __defaultServerSelectionTimeout.Value;
+                var cluster = __cluster.Value;
+                if (!SpinWait.SpinUntil(() => cluster.Description.Servers.Any(s => s.Type == ServerType.ReplicaSetPrimary), timeout))
+                {
+                    throw new Exception($"The cluster didn't find a primary during {timeout}. The current cluster description: {cluster.Description}.");
+                }
+
+                return cluster;
+            }
+        }
+
         public static MessageEncoderSettings MessageEncoderSettings
         {
             get { return __messageEncoderSettings; }
@@ -116,15 +132,9 @@ public static ClusterBuilder ConfigureCluster()
 
         public static ClusterBuilder ConfigureCluster(ClusterBuilder builder)
         {
-            var serverSelectionTimeoutString = Environment.GetEnvironmentVariable("MONGO_SERVER_SELECTION_TIMEOUT_MS");
-            if (serverSelectionTimeoutString == null)
-            {
-                serverSelectionTimeoutString = "30000";
-            }
-
             builder = builder
                 .ConfigureWithConnectionString(__connectionString.Value, __serverApi.Value)
-                .ConfigureCluster(c => c.With(serverSelectionTimeout: TimeSpan.FromMilliseconds(int.Parse(serverSelectionTimeoutString))));
+                .ConfigureCluster(c => c.With(serverSelectionTimeout: __defaultServerSelectionTimeout.Value));
 
             if (__connectionString.Value.Tls.HasValue &&
                 __connectionString.Value.Tls.Value &&
@@ -446,6 +456,17 @@ private static int GetNumberOfMongoses()
             }
         }
 
+        private static TimeSpan GetDefaultServerSelectionTimeout()
+        {
+            var serverSelectionTimeoutString = Environment.GetEnvironmentVariable("MONGO_SERVER_SELECTION_TIMEOUT_MS");
+            if (serverSelectionTimeoutString == null)
+            {
+                serverSelectionTimeoutString = "30000";
+            }
+
+            return TimeSpan.FromMilliseconds(int.Parse(serverSelectionTimeoutString));
+        }
+
         private static string GetStorageEngine()
         {
             string result;

tests/MongoDB.Driver.Tests/Jira/CSharp2564Tests.cs

@@ -39,7 +39,7 @@ public async Task Misbehaved_async_method_should_not_deadlock_server_selection()
             // but then the sync call to RunCommand blocks waiting for a primary and the call to TrySetResult never returns
             // which in turn prevents SDAM from unwinding back to process the next queued heartbeat event so the primary is never found
 
-            var primary = CoreTestConfiguration.Cluster.Description.Servers.Where(s => s.Type == ServerType.ReplicaSetPrimary).Single();
+            var primary = CoreTestConfiguration.ClusterWithConnectedPrimary.Description.Servers.Where(s => s.Type == ServerType.ReplicaSetPrimary).Single();
             void clusterConfigurator(ClusterBuilder builder)
             {
                 builder.Subscribe((ServerHeartbeatSucceededEvent heartbeatEvent) =>